Gunfire control apparatus



April 20, 1943.

GUN FIRE CONTROL APPARATUS M. MENNECIER Filed Jpne 17, 1941 4 Sheets-Sheet l l i /4 K INVENTOR:

Maurice Menneclkr, BY

ATT RN EYS April 20, 1943. M. MENNECIER GUN FIRE CONTROL APPARATUS Filed June 17, 1941 4 Sheets-Sheet 2 INVENTOR': Maur/ce fifenneaer,

April 20, 1943. M. MENNECIER 2,317,233

GUN FIRE CONTROL APPAIRATUS Filed June 17, 1941 4 Sheets-Sheet s' Maurice Mennecz'er; 2 21: '3 BY www ATTORNEYS pril 20, 1943.

M. MENNECI'ER I 2,317,238

GUN FIRE CONTROL APPARATUS Filed June 17, 1941 4 Sheets-Sheet 4 50 INVENTOR W Maurice Mennecze):

- I BY TORNEYS I .der charges in the guns.

GE CONTROL APP Maurice Mennecler, San Fernando, Trinidad, British West Indies, assignor to Schlberger Well Surveying Corporation, Houston, Ken, a

corporation of Delae Application June 17, 1941, Serial No. 398,395 In France August 1, 194a 20 Claims.

The present invention relates to gun firing apparatus and more particularly to new and improved means for selectively and remotely controlling thefiring of gun mechanisms designed to be employed in relatively inaccessible places, such as well casing perforators and formation sample takers, for example, although it is not limited to such use.

Conventional type well casing perforators and formation sample takers comprise in general a long cylindrical body adapted to be lowered into a bore hole and having a plurality of gun bores located in different horizontal planes therein. In the usual practice, it is desirable to fire the guns in the apparatus successively at difierent depths in the bore hole from a remote point at the surface of the earth.

Heretofore, this has been accomplished by using series connected heater filaments of different electrical characteristics to ignite the pow- The filaments corresponding to a plurality of guns are connected in series, one end of the group being grounded and the other end being connected through an electric conductor and suitable switching means to a source of electrical energy at the surface of the earth. The respective guns are fired successively by controlling the intensity of the current fiowing through the conductor.

While this apparatus has proven to be satisfactory in operation, there is a limit to the number of guns that can be fired in this fashion, having in mind the voltage and current limits of a readily transportable source of electrical energy. In addition, if there is a poor contact in one of the series connected filaments, as infrequently happens, no gun in the group including the series connected filaments can be fired.

An object of the present invention, accordingly, is to provide new and improved means for remotely controlling the firing of the guns in apparatus of the above character in which the firing f each gun is accomplished independently of the others,

Another object of the invention is to provide new and improved gun fire control apparatus of the above character in which the igniting filaments in the respective guns are successively and independently connected to a source of electrical energy whereby thy may be fired successively and independently.

A further object of the invention is to provide new and improved gun fire control apparatus of the above character in which identical and in-- the casing II is a conventional terchangeable igniting filaments may be employed.

Additional objects and advantages will become apparent from the following detailed description of several preferred embodiments, taken in conjunction with the accompanying drawings, in

which:

Fig. l is a view in longitudinal section of gun fire control apparatus constructed according to the present invention;

Fig. 1a illustrates a. modification of the apparatus shown in Fig. 1;

Fig. 2 is a modification of the invention employing an expansive, conducting liquid for the purpose of completing the circuit to the respec--' tive resistance filaments;

Fig. 3 is a further modification of the invention in which a column of liquid under pressure is used to control the connection between the source of electrical energy and the respective filaments;

Figs. 4 and 5 are modified forms of the ratu's shownin Fig. 3;

Fig. 6 is a detailed view partly in section illustrating a gun perforator having fire control means constructed according. to the present invention;

Fig. 7 is a cross-sectional view taken along line 1-1 of Fig. 6, looking in the direction of the arrows;

Fig. 8 is a sectional view taken along line 8-8 of Fig. 6, looking in the direction of the arrows:

Fig. 9 is a view in section taken along line 9-9 of Fig. 6, looking in the direction of the arrows;

Fig. 10 illustrates a further embodiment of the invention; and

Fig. is a view in I Oat-Illa of Fig. 10.

Referring now to Fig. l, a bore hole I0 is shown in longitudinal section, within which is fitted a conventional type metallic casing I! usually containing a column of liquid l2. Disposed within type gun perforator l3 which comprises a cylindrical body Iii having a plurality of laterally extending bores lSa, I 5b and He formed therein. The forward portion of the bore |5a is internally threaded to receive an externally threaded barrel portion Ilia within which is formed a centrally located bore Ila adapted to receive a conventional type casing perforating projectile [8a. Similar parts are associated with the bores I51) and I50 respecappasection taken along line tively, and they have been designated by referfired successively and independently by connecting an igniting filament in the powder chamber of each independently and successively to a source of electrical energy'located at the surface of the earth. This is accomplished'by a distributor mechanism comprising a longitudinally extending passage l9 formed in the body 64 which is lined with a layer of suitable insulating material 20, such as rubber, for exampie. is disposed an igniting filament 2ia, one end ofwhich is grounded to the body it at the point 22a and the other end'of which is connected through an insulated conductor to a metallic ring 23:: tightly secured to the layer of insulation 28 within the passage it. In similar fashion the igniting filaments 25b and 2Ic are connected to corresponding contact rings 23b and 230 in the passage H3.

The contact rings 230;, 23b and 230 are adapted to be selectively engaged by a contact member 24 which may comprise a spherical ball made of a conducting material, such as steel for example, which is connected to one end of an insulated conductor 25 wound on a spool 25 secured within a chamber 2i formed in the upper portion of the body l4 and which communicates with the passage 59. The upper end of the conductor 25 is connected through a conventional type slip ring and brush assembly 21a to a conductor 28 within the cable 29 on which the body I4 is supported in the casing i l. The upper end of the conductor 28 is connected to one terminal of a source of electrical energy 30 at the surface of the earth, the other terminal of which is connected through conventional switching means 3| and current indicating means 32 to a ground point 33 also located at the surface of the earth. V

In order that the ball type contact member 24 may be raised within the passage l9, the spool 26 is provided with a ratchet wheel 34 which is adapted to be rotated continuously when the switch 3| is closed, by a pawl 35 operativelyassociated with an electromagnet 36 which is connected to the conductor 28 and. the ground point 31 on the body [4. These elements are conventional and have not been shown in detail in the figure. Other power means such as an electric .motor, for example, may be used for rotating the spool 26.

The apparatus described above is placed in operation by closing the switch 3| at the surface of the'earth. This energizes the electromagnet 36, actuating the pawl 35, winding up the spool 26 and raising the ball type contact member 24 in the passage l3. When the ball type contact member 24 comes into engagement with the contact ring 230; a circuit is completed from the ground point 33 at the surface of the earth through the current indicating means 32, the switch 3|, the source of electrical energy 30, the conductor 28 in the cable 29, the brush and slip ring assembly 21a, the conductor 25, the ball type contact member 24, engaging contact ring 230 and through the igniting filament 2| to the ground point 220. Thiscauses current to flow through the igniting filament 2lc,

thereby igniting the charge of powder at the rear portion of the bore lc and driving the projectile l8c through the bore I and through the adiacent casing II.

If the switch 3| is left closed, the-ball type contact member 24 will successively engage the contact rings 23b and 23a, successively energiz- Within the rear portion of the bore lea ing the igniting filaments 2 lb and 2 la and firing the guns associated therewith. However, if it is not desired to fire the projectiles I80, and 18b. the switch 3| may be opened after the projectile l8c has been fired. This will bring the ball type contact member' 24 to rest at a position intermediate the contact rings 23c and 23b in the passage l9.

It will be apparent that the apparatus described above enables the respective guns in a well casing perforator, formation sample taker or the like to be fired successively and independently from a remote position. Moreover. it will be noted that a bad connection in the circuit of one of the igniting filaments, for example the filament Zlc, will have no effect upon the other filaments Zlb and 2m.

' If desired, a motor driven lead screw may be used in place of the apparatus shown in Fig. l for moving the contact member 24, as shown in Fig. 1a. This may be accomplished by mounting a conventional type lead screw in suitable insulated'bushing 8! and 82 fitted in the insulated passage i9. Threadedly mounted on the lead screw 80 is a contact member 83 provided with a tongue 84 which is adapted to ride in a longitudinal groove 85 formed in the insulating material 20, in order that the contact member 83 will not rotate when the lead screw 80 is rotated. I

[The lead screw 88 is connected at its upper end through suitablegearing 86 to an electric motor 81, one terminal of which is'connected to the conductor 28 in thecable 29, and the other terminal .of which is grounded to the body [4 at the point 31. The. conductor 28 is also connected through a conventional brush and slip ring' assembly 88 to the lead screw 80. It will be apparent that when the motor 81 is energized by closing the switch 3I' at the surface of the .earth, the lead screw 80 will rotate, thereby raisbe noted that the path of the ball type contact member 24 is parallel tothe axis of the body 84, and the axes of the gun barrels lBa, [6b and l6c lie in a vertical plane through the axis of the body |4.- In practical operation it is preferable that the axes of the gun barrels be an gularly spaced about the axis of the body l4. Such an arrangement requires that the conductor 25 follow a helical path about the axis of the body l4. This may be done with-the apparatus shown in Fig. 2. For the sake of clarity, however, the conductor 25 is shown parallel to the axis of the perforator l 3 in Fig. 2. 1

Referring now to Fig.2, the chamber 21 is eliminated and a chamber 38'lined with suitable insulating material and communicating with the passage [9 is formed in the lower portion of the body l4. The upper end of the conductor 25 is directly connected to the conductor 28 in the cable 29 and it. extends'through the body l4 into a casing 39 which is electrically insulated from the body l4 and within which is disposed a conventional type electrical heating element 40. One end of the heating element 40 is connected made of suitable. conducting material to the lower end or the conductor 25 and to the casing 39 at the point 4i, and its other end is grounded to the body l4 at the point Ma. The

chamber 38 is filled with a conductive liquid 42 having a relatively high coefllcient of thermal expansion such as mercury, for example.

When the switch 3| is closed, current is supplied to the electrical heater 4B which generates heat causing the liquid 42 to expand and rise in the longitudinal passage 19. As soon as the level of the liquid 42 reaches the contact ring 280, the circuit to the igniting filament 2|c will be completed through the liquid 42 resulting in the firing of the projectile I8c. In similar fashion, the igniting filaments 2lb and Ma may be energized to fire the projectiles i612 and l8c. If desired, other means may be employed for causing the liquid 42 to rise in the column l9, such as, for example, a conventional type pump driven by an electric motor.

In the embodiment illustrated in Fig. 3, the passage l9 communicates at its, upper extremity with an expansible container 43', such as a flexible bellows, tor example, which is disposed within a chamber 44 formed in the upper portion of the body 14. At ts lower extremity the passage l9 communicates with a second expansible container 45 which again may be a flexible bellows disposed in a chamber 46 formed in the lower portion of the body I4.

The expansion chambers 43 and 45 and the passage I! are filled with a non-conducting, pressure transmitting fluid 41, such as oil, for example, which is maintained under pressure by means of a compression spring 48, the lower end of which is seated in the bottom of the chamber 46. The oil 41 under pressure serves as the means for moving the contact means 49, which in this case may comprise a plurality of balls and threaded upon an uninsulated conductor 50, which is secured to the body Id at the insulated points 50a. and 56b. The balls constituting the contact member 49 are made slightly less in diameter than the diameter of the layer of insulation 26 in the passage l9 so that they act like a piston therein.

In actual practice, the passage 19 will comprise a flexible tube made of insulating material such as rubber, for example, which is disposed in a helical groove formed in the periphery of the body l4, so that it is in contact with the liquid 12 in the bore hole ill. In addition, the expansible containers 43 and 45 are placed in communication with the bore hole liquid l2 through the passages 43a and 45a, so that the pressures outsideand inside the body 14 are automatically equalized. I

In order to control the movement of the contact means 49, the upper end of the passage I9 is provided with a valv 5| which is normally maintained closed by means of a compression spring 52. The valve 5| is adapted to be opened by means of a conventional type electromagnet 53, which is connected to the conductor 26 in the cable 29 and to the ground point 54 on the body 14.

Before the body I4 is lowered into the bore hole, the spring 48 is placed under compression and the valve 5| is closed. The body I4 is then lowered into the bore hol Ill and when the desired level has been reached, the switch 3! is closed, energizing the electromagnet 53 and opening the valve 5|. At that time, 'the oil 41, compressed by the action of the spring 48 on the expansible container 55, forces the balls constituting the contact means 49 upwardly along the conductor 50 in the passage l9. As the contact means 49 comes into engagement with the contact rings 23c, 23!) and'23a, electrical energy is supplied from the source 30 to the igniting filaments 21c, Zlb and Zia, respectively, firing the guns corresponding thereto,

If it is desired to stop the movement of the balls constituting the contact member 49 after the igniting filament Me has been energized. this may be accomplished. by opening the switch 3| to deenergize the magnet,53 and to permit the valve 5| to close.

It should be noted that after a projectile, for example the projectile 160, has been fired, the fiow oi the bore hole liquid i2 into the bore I50 may possibly ground the contact ring 23c. In such circumstances, if the contact means 49 is still in engagement with the contact ring 230, the electromagnet 53 will be short circuited and will be unable to function. In order to avoid this, it is advisable to insert a protective resistance 65 in series with the conductor 50 to limit the short circuit current to a value which will permit the electromagnet 53 to operate at all times.

Fig. 4 illustrates a modified form of the apparatus shown in Fig. 3 in which a U-shaped passage 56 is formed in the body I4, oneend 51 of which is in communication with the bottom of a chamber 56 formed in the upper portion of the body l4, and the other end 59 of which communicates with the upper portion of the chamber 56. In actual practice the two arms 56a and 56b of the passage 56 will be made of flexible insulating tubing disposed in corresponding spiral grooves formed in the periphery of the body l4 as shown in greater detail in Fig. 6.

Within the chamber 58 is provided a piston 60.

- which is normally urged upwardly by a compression spring 6| to create a pressure diiierential in a body of oil 62 which is contained in the chamber 56 and the passage 56. The end 51 of the passage 56 is provided with'a valve 63 which is normally maintained closed by means of a compression spring 64. As in the embodiment shown in Fig. 3, the valve 63 is adapted to be opened by means of an electromagnet 65 connected to the conductor 28 and to the ground Point 54 on thebody l4.

Before the apparatus shown in Fig. 4 is lowered into the bore hole III, the piston 60 is moved downwardly against the compression spring 6| to the bottom of its stroke and the valve 63 is closed. The body I4 is then lowered into'the bore hole and, at the desired depth, the switch 3| is closed to energize the electromagnet 65 63. When this occurs, the compression spring 6l forces the piston 60 upwardly, applying pressure to the body of oil 62 and .moving the balls constituting the contact means 49 upwardly in arm 56a of the passage 56. From this point on the operation is essentially the same as described above in connection with Fig. 3. 5

If desired, a magnetically controlled piston may be used in place of the piston 60 for applying pressure to the oil 62, asshown in Fig. 5.

This may be done by providing a piston 66 in the chamber 58 which-is adapted to be actuated by means of an electromagnet 61 connected to the conductor 28 and to the ground point 54 on the body l4. The piston 56 is provided with a conventional type check valve 68 which is closed when the piston 66 moves downwardly and is open when the piston 66 moves upwardly in the body of oil 62 contained in the chamber 58 and the passage 56. The piston 66 is normally urged in the upward direction by a compression spring 69 seated in the bottom of the chamber 56..

When the electromagnet 61 is energized by the closing of the switch 3|, the piston 66 is forced downwardly, thereby applying pressure to the body of oil 62 and moving the balls constitutin the contact means 49 upwardly in the passage 56. Upon opening the switch 3|, the compression spring 69 forces the piston 66 upwardly and the check valve 68 therein permits the oil 62 to fiow therethrough.

This embodiment may be so designed that each stroke of the piston 66 will move the balls constituting the contact member 49 a distance exactly equal to the space between two adjacent contacts 230 and 23b, thus enabling the respective guns in the perforator l3 to be fired individually as desired. An important advantage of this modification is that it is not necessary to place the spring 69 under compression before the body I4 is lowered into the bore hole.

As indicated above, in practice it is desirable for the respective guns in the gun perforator to be angularly disposed about its axis, and for the conductor supplying electrical energy to the igniting filaments to traverse a helical path. Figs. 6-9 illustrate how this may be accomplished with the apparatus shown schematically in Figs. 4 or 5.

'Considering now Fig. 6, the passage 56 comprises a flexible tube made of an insulating material, such as rubber, for example, which is retained within a pair of helical grooves I and H formed in the outer wall of the body l4. As shown in greater detail in Fig. 7, the igniting filament MD is grounded to the body l4 at the point 22b and its other end is connected to an insulated conductor 12b which passes through the barrel Nb and into a groove 13b formed in the forward portion of the barrel [6b.

Referring now to Figs. 8 and 9, the conductor 12b passes through an insulating disc 14!), which is secured within a recess 15b by means of the screws 16b (Fig. 6), to a contact block "b embedded therein. The contact block 11b is fitted with a pair of downwardly extending prongs 18b which are adapted to pierce the rubber tube 66 to engage the contact ring 23b therein.

The conductor 60 extends through the tube 56 and it is maintained under tension by means of a conventional spring (not shown). As a result, it is forced against the side of the insulating tube 56 and would normally be in contact with each of the contact rings 23a, 23b and 230. In order to prevent this, the spiral groove III in which the tube 56 is retained is provided with a depressed portion 19!) directly below the contact ring 23b and the lower surface of the disc 14b is so shaped as to force the contact ring 29b into the groove 19b as shown in Fig. 9. Similar provisions are made for the contact rings 23a and 230. In this fashion the conductor 60 may be made to pass along the axes of the contact rings 23a, 23b and 23c and out of contact therewith. With this construction, the conductor 66 will come into contact with the contacts 23a,

23b and'23c only when the balls constituting the contact means 49 move into the vicinity of the respective contacts.

In certain cases, it may be desirable to lower the perforating apparatus into the bore hole on a string of drill pipe instead of an electric cable. The embodiment illustrated in Figs. 10 and 10a of the drawings is especially adapted for this purpose. It is similar to the one shown in Fig. 4 of the drawings, except that the-upper end 69 of the passage 56 is connected to one end of a chamber 89 in the body l4. The other end 61 of the passage 56 communicates through a passage 90 with the opposite end of the chamber 69. Secured at the bottom of the drill pipe 9| and mounted in the chamber "is the rotor 92 of a conventional type rotary pump (Fig. 100.). The

igniting filaments are energized by a suitable source of electrical ener y, such as a battery 93, mounted in a chamber 94 in the body l4, which source is grounded at the point 96 to the body l4, its other terminal being connected to the conductor 59 in the passage 56. Rotation of the body I4 is prevented by suitable guide springs 96, and a port 91 is provided in the drill pipe ll to permit circulation of the bore hole liquid therethrough.

The respective igniting filaments are adapted to be energized by rotating the string of drill pipe 9| to produce a liquid pressure differential in the passage 56. The pump may be calibrated so that the position of the contact member 49- at any instant can be determined, or it may be designed to move the contact member 49 from one contact to the next for one complete 'turn of the string of drill pipe,9l. After the last shot has been fired, the contact member 49 will be moved past the entrance to the passage 96, so that extended operation of the pump may be effected as a safety'measure before the perforator is withdrawn from the bore hole. This also enables the drill pipe 9! to be rotated indefinitely and the circulation of the bore hole fluid I! to be.

maintained as long as desired before withdrawing the perforator l3 from the bore hole III.

From the foregoing it will be apparent that the invention provides simple and highly effective gun fire control apparatus for independently i and successively firing a plurality of explosive charges in a body adapted to be lowered into a bore hole, such as a well casing perforator or a formation sample taker, for example. By virtue of the novel distributor mechanism employed by the applicant, each igniting filament may be energized separately and independently of the others, so that any defective filaments will not affect the operation of those that are in good condition.

While several specific embodiments have been to be, limited thereto, but is susceptible of numerous changes in form and detail within the scope of the appended claims.

I claim:

1. Gun fire control mechanism for remotely controlling the firing of a plurality of explosive charges in a body adapted to be lowered into a well, comprising a plurality of igniting filaments in the body each having one terminal connected to ground, an insulated conduit associated with said body and having a. plurality of contacts therein, each connected to the other terminal of a corresponding igniting filament, a contact member in said conduit and adapted to engage said contacts successively, means, controllable from the surface of the earth, for actuating said contact member to cause it to engage only one or any desired number of said contacts succesasmase' mitting fluid in said lower, chamber, means for an electrical connection between the other terminal of said source and said contact member.

2. Gun fire control mechanism for remotely controlling the firing of a, plurality of explosive charges in a body adapted to be lowered into a well, comprising a plurality of igniting filaments in a body each having one terminal connected to ground, an insulated conduit associated with said body and having a plurality of contacts therein, each connected to the other terminal of a corresponding igniting filament, a contact member in said conduit and having an insulated electrical conductor connected thereto, electri-. cally operated means for moving said conductor through said conduit to cause said contact member to engage the contacts successively, a source of electrical energy at the surface of the earth and having one terminal connected to ground, and an electrical connection between the other terminal of the source and said insulated conductor.

3. Gun fire control mechanism for remotely controlling the firing of a plurality of explosive charges in a body adapted to be lowered into a well, comprising a plurality of igniting filaments in the body each having one terminal connected,

to ground, an insulated conduit associated with said body and terminating at its lower extremity in an insulated chamber in the body, a plurality of spaced apart contacts in said conduit, each connected to the other terminal of a corresponding igniting filament, a body of conducting fiuid having a relatively high temperature coefficient of expansion in said chamber, electrical heating means in said chamber, a source of electrical energy at the surface of the earth having one terminal connected to ground, and an electrical connection between the other terminal of said source and said body of fluid.

4. Gun fire control mechanism for remotely controlling the firing of a plurality of explosive charges in a body adapted to be lowered into a well, comprising a plurality of igniting filaments in the body, each having one terminal connected to ground, an insulated conduit associated with said body and terminating at its lower extremity in a chamber having a pressure transmitting fluid therein, a plurality of spaced apart contacts in said conduit each connectedto the other terminal' of a corresponding igniting filament, a

conductor in said conduit having contact means slidablymounted thereon, said contact means applying pressure to said body of fluid, valve means for closing 01? the upper end of said conduit, and electrical means connected to said source and ground for controlling said valve means.

6. Gun fire control apparatus forremotely controlling the firing of a plurality of explosive charges in a body adapted to be lowered into a bore hole, comprising a plurality of igniting filaments in the body, each having one terminal connected to ground, an insulated conduit associated with said body and terminating at its upper and lower extremities in expansible chambers, a conductor in said conduit having contact means slidably mounted thereon, said contact means being adapted to fit snugly within said conduit, a source of electrical energy at the sur-' face of the earth having one terminal connected to ground, and a second terminal connected to said conductor in the conduit, a current limiting resistance connected in series with said lastnamed conductor, a body of pressure transmitting fluid in said lower chamber, means for applying pressure to said body of fluid, valve means for closing oil the upper end of said conduit, and electrical means connected to said source and groundfor controlling said valve means.

7. Gun fire control apparatus for remotely controlling the firing of a plurality of explosive charges in a body adapted to be lowered into a bore hole, comprising a plurality of igniting filaments in the body each having one terminal connected to ground, means forming a chamber in being adapted to flt snugly in said conduit, means for creating a pressure differential about said contact means to cause it to engage saidcontacts successively, a sourceof electrical energy at the surface of the earth having one terminal connected to ground; and an electrical connection between the other terminal of said source and said conductor in the conduit.

5. Gun fire control apparatus for remotely controlling the firing of 'aplurality of explosive charges in a body adapted to be lowered into a bore hole, comprising a plurality of igniting filaments in the body,'each having one terminal connected to ground, an insulated conduit associated with said body and terminating at its upper and lower extremities in expansible chambers, a conductor insaid conduit having contact means slidably mounted thereon, said contact means being adapted to fit snugly within said conduit,

a source of electrical'energy at the surface of the earth, having one terminal connected to ground, and-via second-terminal connected to said conductor in the conduit, a body 01' pressure transthe upper portion of the body, an insulated conduit associated with the body and having its upper end in communication with one end of said chamber, a second conduit communicating at its upper end with the other end of said chamber and at its lower end with the lower end of said first conduit, a plurality oi spaced apart contacts in said first conduit, each connected 'to the other end of a corresponding igniting filament, a conductor in said first conduit having contact means slidably mounted thereon, said contact means being adapted ,to fit snugly in said conduit, a'

source of electrical energy at the surface of the earth having one terminal connected to ground and another terminal connected to said conductor in the conduit, a piston in said chamber, a body of pressure transmitting fluid in the portion of said chamber which is in communication with said second conduit, means urging said piston normally in the direction to compress said fluid, valve means for closing theupper end of said first conduit, and electrical means connected to said source and to ground for controlling said valve means.

8.- Gun fire control apparatus for remotely controlling the firing' of a plurality of explosive charges in'ia body adapted to be lowered into a bore hole, comprising a plurality of igniting filaments in the body each having one terminal connected to ground, means forming a chamber in the upper portion of the body, an insulated conduit associated with the body and having its upper end in communication with one end of said chamber, a second conduit communicating at its upper end with theother end of said chamber and at its lower end with the lower end of said first conduit, a plurality of spaced apart contacts said second conduit, means urging said piston normally in the direction to release the pressure in the said fluid, electric means connected to said source and to Eround for moving said piston in the direction to compress said fluid, and check valve means in the piston for providing communication between the opposite sidesof said,

piston when the latter is released after having been actuated by said electric moving means.

9. Gun fire control apparatus for remotely con,- trolling the firing of a plurality of explosive charges adapted to be lowered into a bore hole, comprising a plurality of igniting filaments in the body, each having one terminal thereof connected to ground, means forming a spiral groove in the periphery of said body, an insulated conduit disposed in said groove, a plurality of spaced apart contacts in said conduit, each being connected to the other terminal of a corresponding igniting filament, contact means movably mounted in said conduit, a source of electrical energy at the surface of. the earth having one terminal connected to ground and another terminal connected to said contact means, and means for moving said contact means to bring it into engagement successively with said respective contacts.

10. In apparatus for use in bore holes, the combination of a body adapted to be lowered into a bore hole, said body having at least one gun bore therein terminating rearwardly in a powder chamber, means forming a groove in the periphery of the body, an insulated tube disposed in said groove and having a contact therein, an

igniting filament in said powder chamber havingone terminal grounded to the body and a second terminal connected to said contact, contact means slidably mounted in said conduit, a source of electrical energy at the surface of the earth having one terminal connected to ground and a second terminal .connected to said contact means, and means for moving said contact means to bring it into engagement with said contact.

11. In apparatus for use in bore holes, the

combination of a body adapted to be lowered 1 into a bore hole, said body having a groove formed therein, an insulated conduit in said groove, 9. contact ring in said conduit, an insulated conducting member secured to said body and having a pointedportion extending through said conduit to engage said contact ring, and an igniting filament in said body having one terminal connected to ground and a second terminal connected to said conducting member.

12. In apparatus for use in bore holes, the

- combination of a body adapted to be lowered tact ring in said depression in the groove,

-. whereby the conductor may be kept out of en' gagement with the contact ring, a metallic member in said insulating member and having a pointed portion extending through said conduit into contact with said contact ring, an igniting filament in said powder chamber, having oneterminal grounded to the body and a second terminal connected to said metallic member. contact means slidably mounted on said conductor in the conduit, a source of electrical energy at the surface of the earth having one terminal connected to ground and a second terminal connected to said conductor in the conduit, and means for moving said contact means in the conduit to engage said contact ring.

14. Gunfire control mechanism for remotely controlling the firing of a plurality of explosive charges in a body adapted to be lowered into a well, comprising a plurality of igniting filaments in the body, each having one terminal connected to ground, an insulated conduitassociated with said body and having a plurality of contacts therein, each connected to the other terminal of a corresponding igniting filament, a lead screw mounted in said conduit and insulated therefrom, a contact member threaded on said lead screw and adapted to engage said contacts, power means for actuating said lead screw, a source of electrical energy having one terminal connected to ground, and an electrical connection between the other terminal of said sourc and said lead screw.

15. Gun fire control apparatus for remotely controlling the firing of a plurality of explosive charges in a body adapted to be lowered into a bore hole on a' string of drill pipe, comprising a plurality of igniting filaments in the body, each having one terminal connected to ground, pumping means in the upper portion of said body and adapted to be actuated by said string of drill pipe, a conduit associated with the body and having its upper end in communication with said pumping means, an insulated conduit communicating at its upper end with said pumping means andat its lower end with the lower end of said first conduit, a plurality of spaced apart contacts .in said insulated conduit, each connected to the other end of a corresponding igniting filament, a conductor in said insulated conduit, having contact means slidably mounted thereon, a body of pressure transmitting fiuid in said first and second conduits and pumping means, and a source of electrical energy in the body, having one terminal connected to ground and another terminal connected to said conductor in the conduit.

16. In apparatus for use in wells, the combination of a body adapted to be lowered into a borehole and having a plurality of electrical circuits associated therewith, a source of elecof spaced apartcontacts therein, electrical conneotions between said contacts and said respective electrical circuits, a movable contact member in said conduit and electrically connected to the other terminal of said source of electrical energy, and means, controllable from the surface of the earth, for actuating said contact member to cause it to engage only one or any desired number of said contacts as desired,

17. In apparatus for use in wells, the combination of a body adapted to be lowered into a bore hole and'having a plurality of electrical circuits associated therewith, a source of electrical energy having one terminal connected to said electrical circuits, an insulated conduit associated with the body and having a plurality of spaced apart contacts therein, electrical connections between said contacts and said respective electrical circuits, a movable contact memher in said conduit and electrically connected to the other terminal of said source of electrical ener a body of pressure transmitting fluid in said conduit, means for producing a pressure difierential about said contact member to cause it to engage said contacts, and means, controllable from the surface of the earth, for render= ing said pressure difierential producing means operative to move said contact member into engagement with only one or any desired number of said contacts as desired.

18, In apparatus for use in a bore hole, the combination oi as body adapted to be lowered into a bore hole and having a plurality of electrical circuits associated therewith, means forming a longitudinally extending groove in the periphery of the body, a plurality of spaced apart, insulated contacts mounted in said groove, said contacts being elmtrically connected to said respective electrical circuits, a movable contact member adapted to as said contacts, gui means in said groove for said contact member, a source of electrical energy connected to said contact member and to said electrical circuits, and means tor moving said contact member in bring it into engagement with said respective contacts.

19. In apparatus for use in bore holes, the combination of a body adapted to be lowered into a bore hole, said body having a plurality of electrical circuits associated therewith, means forming a groove in the periphery of the body, an insulated conduit disposed in said groove and having a plurality of contacts therein, said contacts being, electrically connected to said respective electrical circuits, contact means slidably mounted in said conduit,'a' source of electrical energy having one terminal connected to said plurality of electrical circuits and another terminal connected to said contact means, and 'niea'ns for moving said contact means to bring it into engagement with said contacts.

20. In apparatus for use in bore holes, the combination of a body adapted to be lowered into a bore hole, said body having a plurality of elec trical circuits associated therewith, means forming a groove in the periphery of the body, an insulated conduit disposed in said groove and having a plurality of contacts therein, said contacts being electrically connected to said respective electrical circuits, contact means slidably mounted in said conduit, a source of electrical energy having one terminal connected to said plurality of electrical circuits and another terminal connected to said contact means, a body of pressure transmitting fluid in said conduit, and means for producing a pressure difierential about said contact means to move it into engagement with said respective contacts.

MAURICE M 

